Universitas Brawijaya

KEMENTERIAN RISET, TEKNOLOGI DAN PENDIDIKAN TINGGI

UNIVERSITAS BRAWIJAYA

FAKULTAS TEKNIK

PROGRAM STUDI TEKNIK KIMIA

Jl. Mayjen Haryono 167, Malang 65145, Indonesia

Telp. : +62-341-587710, pswd :1333, 1139, 1245, 1229; Fax : +62-341-574140

website : E-mail :

Ujian: Akhir Semester

Mata Kuliah: Kimia Fisika

Kelas A/B: Kelas B

Semester: Genap 2015/2016

Prodi: Teknik Kimia

Total points: 120 pts

(10 pts)This problem deals with 1st law thermodynamics concept

A gas (assume as ideal gas) is enclosed within a chamber that is fitted with a frictionless piston. The piston is then pushed in, thereby compressing the gas, what will happen to the state of that gas according to the 1st law of thermodynamics? Is that possible when there is no heat flows in the chamber, the temperature of that gas increases? Please explain for your yes or no answer!

This problem deals with state and path function

Consider the cyclic process below representing a heat engine.

If there is 1.00 mol of ideal gas (Cp = 7/2R and Cv = 5/2R), the temperature at each point in the cycle is as follows:

Temp at A / Temp at B / Temp at C / Temp at D
487 K / 975 K / 487 K / 244 K

(5 pts) Write the sign “+”, “-“, or “0” for the value of ΔU, q, and w in each process and overall process (AB, BC, CD, DA, and overall)
(15 pts) Calculate enthalpy change, internal energy change, heat and work produced and absorbed for each process and overall process.

This problem deals with reversible work

A mass of 1000 kg is placed on a 1m x 1m plate which acts as a piston over a 1m x 1m x 1m volume of perfect gas at 298 K. The gas is originally in equilibrium with the external pressure of 1 atm (101325 Pa).

a. (15 pts) How much will the piston descend if the temperature is kept constant? The gravitational acceleration is g = 9.80 ms-2

b. (15 pts) Calculate the work performed on the gas, and the heat absorbed by the gas in the process.

c. (5 pts) Is this compression a reversible process (in the thermodynamics sense)? Please give a reason for your yes or no answer

4. This problem deals with Thermocemistry calculation

(20 pts) Given the data at 25 °C :

Ti (s) + 2Cl2 (g) TiCl4 (l) Standard Molar Enthalpy of formation= -804.2 KJ/mol

Ti (s) + 2Cl2 (g)TiCl4 (g) Standard Molar Enthalpy of formation= -763.2 KJ/mol

For the reaction:

a. Calculate for TiCl4(l) at 25 °C

b. Calculate for this reaction at 135.8 °C, the boiling point of TiCl4(l)

5. This problem deals with phase diagram of single and binary compound

a. (15 pts) Prior to the discovery that freon-12 (CF2Cl2) was harmful to Earth’s ozone layer, it was frequently used as the dispersing agent in spray cans for hair spray, etc. Its enthalpy of vaporization at its normal boiling point of –29.2°C is 20.25 kJ mol-1. Estimate the pressure that a can of hair spray using freon-12 had to withstand at 40°C (the temperature of a can that has been standing in sunlight). Assume that ΔvapH is a constant over the temperature range involved. (Hint: Use Clausius-Clapeyron equation)